The objectives of the proposed work are to develop immunoadsorbents for nonhistone chromatin proteins (NHCP's) and to use these immunoadsorbents both analytically to assess the organ specificity of NHCP's and preparatively to isolate tumor-enriched NHCP's. Immunoadsorbents will be made by covalently linking antibodies against unfractionated NHCP's to cyanogen bromide-activated Sepharose. The organ specificity of nonhistone proteins will be examined by applying NHCP's from rat kidney, brain, and spleen to an immunoadsorbent against rat liver NHCP's. Proteins which are not immunologically cross reactive with nonhistones from liver and which are either distinct to or greatly enriched in kidney, brain, or spleen should not be bound significantly by the column. Tumor-enriched NHCP's will be isolated from HTC cells (a cell line derived from the transplantable rat hepatoma 7288c) and from the transplantable renal adenocarcinoma MK3 by applying NHCP's from these neoplastic sources to immunoadsorbents against normal rat liver NHCP's and rat kidney cortex NHCP's, respectively. DNA-binding proteins in the groups of tumor-enriched non-histones will be obtained by DNA-cellulose chromatography, and individual proteins then purified by standard techniques of protein isolation. The binding of the purified proteins to DNA will be investigated to determine if the proteins bind selectively to particular DNA sequences. In these studies the existing nitrocellulose filter procedure for the detection of protein-DNA complexes will be used, and for the direct determination of dissociation constants a procedure will be developed which takes advantage of the exclusion of DNA from an agarose gel which the proteins can penetrate.